package com.wc.codeforces.DP.线性DP.Array_Fix;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

/**
 * @Author congge
 * @Date 2024/6/22 15:47
 * @description https://codeforces.com/problemset/problem/1948/B
 */
public class Main {
    static FastReader sc = new FastReader();
    static PrintWriter out = new PrintWriter(System.out);
    static int N = 55;
    static int[] a = new int[N];
    // f[i][0] 表示当前数不拆, f[i][1] 表示当前数拆
    static boolean[][] f = new boolean[N][2];
    static int n;

    public static void main(String[] args) {
        int T = sc.nextInt();
        while (T-- > 0) {
            n = sc.nextInt();
            for (int i = 1; i <= n; i++) {
                a[i] = sc.nextInt();
                f[i][0] = f[i][1] = false;
            }
            f[0][0] = f[0][1] = true;
            for (int i = 1; i <= n; i++) {
                if (a[i] >= a[i - 1]) f[i][0] |= f[i - 1][0];
                if (a[i] >= a[i - 1] % 10) f[i][0] |= f[i - 1][1];
                int x = a[i] / 10, y = a[i] % 10;
                if (x > y) continue;
                if (x >= a[i - 1]) f[i][1] |= f[i - 1][0];
                if (x >= a[i - 1] % 10) f[i][1] |= f[i - 1][1];
            }
            if (f[n][0] | f[n][1]) out.println("YES");
            else out.println("NO");
        }
        out.flush();
    }
}

class FastReader {
    StringTokenizer st;
    BufferedReader br;

    FastReader() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    int nextInt() {
        return Integer.parseInt(next());
    }

    String nextLine() {
        String s = "";
        try {
            s = br.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return s;
    }

    long nextLong() {
        return Long.parseLong(next());
    }

    double nextDouble() {
        return Double.parseDouble(next());
    }

    // 是否由下一个
    boolean hasNext() {
        while (st == null || !st.hasMoreTokens()) {
            try {
                String line = br.readLine();
                if (line == null)
                    return false;
                st = new StringTokenizer(line);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return true;
    }
}
